Parasitology: Dipterans Flashcards
T/F: Dipterans undergo complete metamorphosis.
True
What are the life stages of a dipteran?
egg -> larva -> pupa -> adult
With some exceptions, adult dipterans have how many pairs and what type of characteristic in their wings?
- 1 pair of membranous wings
Why do we dislike flies?
- can cause fly worry
- fly bites, leading to decreased production
- disease transmission
- parasitism by larval flies (obligate and facultative)
Musca (filth flies): Main hosts biting vs. nonbiting distinguishing characteristics importance preferred sites on animals locations of immature stages
- General hosts
- nonbiting
- housefly-like
- fly worry
- no preferred site
- filth!
Musca autumnalis: Main hosts biting vs. nonbiting distinguishing characteristics importance preferred sites on animals locations of immature stages
- cattle
- nonbiting
- looks like house fly
- tearing, FW, transmits Moraxella
- face, around eyes
- fresh feces
Haematobia irritans: Main hosts biting vs. nonbiting distinguishing characteristics importance preferred sites on animals locations of immature stages
- cattle and horses
- biting
- sit on dorsum, heads pointing down
- FW, production loss, FBD
- dorsum, ventrum in hot weather
- fresh feces
Stomoxys calcitrans: Main hosts biting vs. nonbiting distinguishing characteristics importance preferred sites on animals locations of immature stages
- livestock and others
- biting
- house fly-like, mouth parts at right angle to head
- FW, FBD
- legs, lower body
- decaying organic material
Simulidae (black flies): Main hosts biting vs. nonbiting distinguishing characteristics importance preferred sites on animals locations of immature stages
- mammals and birds
- biting
- small, black, humpbacked
- FW, FBD, vector for avian hemprotozoa
- upper body, thin hair
- rapidly flowing water
Culicoides (midges, no-see-ums): Main hosts biting vs. nonbiting distinguishing characteristics importance preferred sites on animals locations of immature stages
- mammals and birds
- biting
- tiny
- FW, FBD, transmits EHD, bluetongue
- thin-haired areas
- aquatic or semiaquatic
Tabanids: Main hosts biting vs. nonbiting distinguishing characteristics importance preferred sites on animals locations of immature stages
- cattle and horses
- biting
- big eyes, deer flies have wing stripes
- FW, good mechanical vectors
- FW, FBD, disease vector
- no preferred site
- water
Moquitoes: Main hosts biting vs. nonbiting distinguishing characteristics importance preferred sites on animals locations of immature stages
- all
- biting
- proboscis longer than head + thorax
- FW, FBD, disease vectors
- no prefered sites
- water
T/F: Musca domestica and others (filth flies, gnats, and nuisance flies) are parasites.
false, they are not parasites
What are the biggest concerns of Musca domestica and similar flies?
- disease vectors
- FW can interfere with normal behavior and production
Where are Musca domestica eggs typically laid?
decaying organic material
What is the generation time of the housefly?
2 week cycle
What is the common name for Musca autumnalis?
face fly
what is the scientific name for the face fly
Musca autumnalis
What is the importance of Musca autumnalis?
- cause fly worry
- irritate mucosa, cause inflammation and tearing
- *** transmits Bovine pinkeye (mechanical vector of Moraxella bovis)
Musca autumnalis is an important fly of what species?
cattle
What do female Musca autumnalis eat?
protein-rich secretions (tears, mucus, etc.)
What are some general concerns regarding adult biting flies?
- cause fly worry
- can transmit disease
- can cause fly bit dermatitis
What is fly bite dermatitis
an allergic reaction to antigens injected during fly bites
What are some examples of biting flies?
- Stomoxys calcitrans
- Haematobia irritans
- Simuliidae (black flies)
- Tabanidae (horse/deer flies)
- Culicidae (mosquitoes)
- Culicoides
What is the common name of Stomoxys calcitrans?
the stable fly
What is the scientific name of the stable fly?
Stomoxys calcitrans
Physical characteristics of Stomoxys calcitrans
- looks like a house fly, but with a proboscis
How often do stable flies visit the host?
1-2x per day
T/F: stable fly bites aren’t painful.
BULL FUCKING SHIT THEY DON’T
False.
Where do stable flies spend most of their time?
in the environment
Where do Stomoxys prefer to bite?
legs and flanks
What are some reactions to Stomoxys bites that we can see?
- host stamps foot, livestock bunch together
- lesions on the tips of dog ears
Where do Stomoxys calcitrans lay their eggs?
in decaying organic material
love manure mixed with straw
What important issues are caused by Stomoxys calcitrans?
- fly worry
- FBD
T/F: Stomoxys calcitrans are not an important disease vector.
true
What is the most important external parasite of cattle?
Haematobia irritans (the horn fly)
What is the scientific name of the horn fly?
Haematobia irritans
What is the common name of Haematobia irritans
the horn fly
General characteristics of Haematobia irritans?
- small flies
- sit on dorsum (ventrum when hot) of cattle and horses (when cattle are nearby)
T/F: Adult H. irritans are resident parasites.
true
Where are H. irritans legs laid?
- fresh manure
how often do H. irritans feed on host?
up to 20x per day
What are the major issues associated with H. irritans?
- decreased production
- FW
- FBD
- may carry bacteria carrying mastitis
What dipterans belong in family Tabanidae?
horse and deer flies
What is the general physical appeance of dipterans from Tabanidae?
- in general, big flies, big eyes, stout body
- deer flies often have striped wings
Where do Tabanids lay their eggs
near water
What are the importance of Tabanids in hosts?
- annoyance (very painful bites)
- excellent mechanical vectors of disease
T/F: Tabanids have mouth parts with a kind of “knife” that they use to cut the host in order to feed
true
Why are Tabanids such good mechanical vectors?
they move from animal to animal rapidly
What flies are typically associated with family Culicidae?
mosquitoes
General physical appearance of Culicidae
small, delicate flies, long mouthparts
Where do members of family Culicidae lay their eggs
in water (some variation occurs between genera regarding standing vs moving water)
What are the important issues regarding family Culicidae?
- FW, FBD
- IMPORTANT disease vector!!!!
What kinds of diseases can family members of Culicidae be vectors for?
- heartworms
- equine encephalitis viruses
- avian malaria
What flies are associated with family Simuliidae?
black flies, buffalo gnats
What’s a key physical characteristic of a buffalo gnat?
the lil hump on its back
What are some concerns regarding simuliidae?
- intense fly worry, capable of interrupting feeding, can cause stampedes in large numbers
Where do Simuliidae typically lay their eggs?
rapidly movign water
Where do simuliidae typically bite or cause fly worry?
upper body of host
Where are Simuliidae more of a problem geographically?
the northeast, Canadian plains, and other areas
What diseases can Simuliidae be a vector for?
- Avian hemoprotozoa
- Eastern Equine Enchephalitis
- vesicular stomatitis
What flies are associated with family Culicoides?
No-see-ums, midges
General physical characteristics of culicoides
tiny flies, able to get through screens
where would you find Culicoides larvae?
moist soil or water
Concerns regarding Culicoides
- Fly worry
- FBD in horses
- disease transmission
Which diseases can Culicoides be vectors?
- bluetongue in ruminants
- epizootic Hemorrhagic disease in deer
- some nematodes
What are some mechanical methods of fly control for large animals?
- window screens, doors
- bug zappers (only emotionally satisfying)
- traps
What are some method of fly control in manure?
- get rid of it
- feed-through pesticides that kill the larvae
- parasitic (parasitoid) wasps
What is a parasitoid wasp?
a wasp whose larvae feed on the fly pupa
What are some methods of fly control for food animals?
- dust bags, back rubbers
- ear tags that have insecticide on them
- pour-ons (pyrethroids, macrolides, most common)
What are some methods of fly control for horses?
- repellents, sprays, pour-ons
- masks, fly sheets, screens in barns
What is myiasis?
Any infection due to the invasion of the tissues or cavities of the body by the larvae of dipterous insects
What flies are involved in cutaneous myiasis?
- fly strike
- maggots
What flies are involved in internal myiasis?
- grubs
- warbles
bots
what flies are associated with bot fly family?
bot flies
What is a representative species of bot flies?
- Gastrophilus spp
- Cutererbra spp
- other animals and birds have their own
What is common name of Gastrophilus?
horse bots
what is the common of Cuterebra?
rodent bot flies
What is fly strike caused by?
- larvae of blow flies (calliporids) and some others
- these are commonly called maggots
What are the physical appearance of blow flies?
- metallic green, blue, bronze
What flies are associated with family Calliphoridae
blow flies, fly strike flies
What is the life cycle of flies involved in myiasis?
- eggs are laid in organic material
- the larvae then feed on that necrotic material
What are females attracted by when looking for places to lay eggs?
- secretions from wounds, fecal material, etc.
- They’re attracted to the smell of necrosis and putrefaction)
What are some clinical signs of fly strike?
- presence of maggots
- animal may be depressed due to toxemia
How do you treat fly strike?
remove the maggots, maybe place patient on antibiotic after
What are some methods of preventing fly strike?
- wound spray in fly season
- castrate, dehorn, etc. before fly season
T/F: Fly strike maggots are obligatory parasites.
false
female adult couldn’t tell difference between a living and dead animal.
T/F: Medical use of maggot in wound healing exists.
true
What is the scientific name of the screwworm fly
Cochliomyia hominovorax
What is the common name of Cochliomyia hominovorax?
screwworm, screwworm fly
What sets screwworm fly strike apart from other fly strikes?
It requires living tissue
T/F: Screwworm infestations are a reportable disease.
true
How did the US eradicate screwworms previously?
sterile male release program
T/F: screwworm outbreak is occurring currently in the Florida Keys
true
What are the bot fly larvae called?
bots, grubs, or warbles
T/F: bot fly larvae are obligate internal parasites
true
When do bot fly larvae pupate?
in the environment, after they leave the host
T/F: Bot flies are very hairy
true
Where are Gastrophilus eggs laid?
on the face or legs of equids
How do Gastrophilus larvae enter the host?
they are licked off from the site of egg attachment by the host, and then enter the GI tract
Where do Gastrophilus larvae prefer to be?
in the stomach
how long do Gastrophilus larvae remain in the stomach
10-12 months
Describe the life cycle of Gastrophilus.
- Eggs laid on face or legs of equids
- eggs hatch move into mouth
- migrate in gums and tongue briefly
- move to stomach, remain 10-12 months
- pass out in manure
- pupate on the ground
- become adults, then mate, cycle restarts
Clinical signs of Gastrophilus
- very few clinical signs
- not very pathogenic
- sometimes see mouth lesions or stomach ulceration
How does one diagnose Gastrophilus infestation
see the flies, eggs on the legs
How do you treat for Gastrophilus
- Typically an annual treatment in fall (after the first frost)
- can use warm water to stimulate egg hatching, then wash the larvae away
- use bot combs
What is the primary host of Cuterebra spp?
rodents and rabbits
Where are Cuterebra eggs typically laid
near burrows or along trails
Where do Cuterebra larvae develop on the host?
a subcutaneous cyst
T/F: Cuterebra spp infections cannot occur in dogs and cats
false
they can be infested
Where do Cuterebra Larvae pupate
they pupate on the ground
Where would you find Cuterebra spp on dogs or cats?
- around the head or neck
- looks like a boil (furuncle)
Clinical Signs of Cuterebra
- observation of lump
- may develop a secondary infection
- occasional cases of abnormal migration, resulting in eye lesions or CNS disease
Treatment of Cuterebra
- remove carefully, and use antibiotics as needed for secondary infection prevention
- DO NOT SQUEEZE IT, ITS NOT A ZIT
Which bugs belong to the order Hemiptera?
Triatomid bugs, aka Kissing bugs (“true bugs”)
- Cimex (bed bugs
What is the primary concern regarding Triatomids
they can transmit the protozoan illness Chagas Disease to humans
T/F: if a house is infested with bed bugs, you won’t see bites on pets.
false, they’ll definitely be there
